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 A328500 Number of inversion sequences of length n avoiding the consecutive pattern 102. 1
 1, 1, 2, 6, 22, 96, 492, 2902, 19350, 143918, 1181540, 10614698, 103589738, 1091367634, 12346368424, 149276823258, 1921099070062, 26220186000950, 378308908684300, 5753387612678314, 91988260677198002, 1542570178562361018, 27072325866355742048 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Alois P. Heinz, Table of n, a(n) for n = 0..250 Juan S. Auli, Pattern Avoidance in Inversion Sequences, Ph. D. thesis, Dartmouth College, ProQuest Dissertations Publishing (2020), 27964164. Juan S. Auli, Sergi Elizalde, Consecutive Patterns in Inversion Sequences, arXiv:1904.02694 [math.CO], 2019. See Table 3. FORMULA a(n) ~ n! * c * d^n * n^alfa, where d = 1/A240885 = 1/(sqrt(2) * InverseErf(sqrt(2/Pi))), alfa = 0.294868853646259565..., c = 2.22826071050847602... - Vaclav Kotesovec, Oct 19 2019 MAPLE b:= proc(n, j, t) option remember; `if`(n=0, 1, add( `if`(i<=j or i>=t, b(n-1, i, j), 0), i=1..n)) end: a:= n-> b(n, 0\$2): seq(a(n), n=0..25); # Alois P. Heinz, Oct 18 2019 MATHEMATICA b[n_, j_, t_] := b[n, j, t] = If[n == 0, 1, Sum[If[i <= j || i >= t, b[n - 1, i, j], 0], {i, 1, n}]]; a[n_] := b[n, 0, 0]; a /@ Range[0, 25] (* Jean-François Alcover, Mar 01 2020, after Alois P. Heinz *) CROSSREFS Cf. A049774, A071075, A200404. Sequence in context: A253948 A248836 A351919 * A180389 A177389 A130907 Adjacent sequences: A328497 A328498 A328499 * A328501 A328502 A328503 KEYWORD nonn AUTHOR Vaclav Kotesovec and Juan S. Auli, Oct 17 2019 STATUS approved

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Last modified December 9 11:21 EST 2022. Contains 358700 sequences. (Running on oeis4.)